Decades of development and natural vegetation changes have combined for a loss of grasslands in Calverton and across eastern Long Island, leaving endangered animals with smaller habitats to roam, state environmental officials say.

This weekend, in honor of Earth Day, the state Department of Environmental Conservation is seeking the public’s help in reclaiming some of those grasslands. DEC staffers will be leading cleanup efforts Sunday at the Otis Pike Preserve in Calverton, state-owned property set aside for recreational use, like hiking, biking and hunting.

The preserve is home to native species, including endangered short-eared owls, eastern meadowlarks, northern harriers and woodcock birds, officials say.

Volunteers will be removing invasive species and woody vegetation,under the direction of DEC wildlife staff. They will also reseed the area to promote regrowth of native grasses.

FedEx employees have already volunteered to help.

“Grasslands are one of the most important and imperiled habitats across our state,” said DEC regional director Peter Scully.

Volunteers are being asked to meet at 10 a.m. outside Otis Pike Preserve on Route 25A (Parker Road) just north of the Route 25 (Middle Country Road) intersection in Calverton, parking spot 36.

Long-sleeved shirts, pants, boots and especially gloves are recommended. Volunteers should also prepare themselves with food and water, sun protection and bug protection and hand-cutting tools to trim shrubs, according to a release.

“DEC thanks FedEx for their initiative to help expand grasslands on Long Island and hopes many more volunteers will assist in this needed effort,” Mr. Scully.